_package("alz.util");

/**
 * 日期格式化工具类
 * @see http://clin8888.javaeye.com/blog/309359
 * Date Format 1.2.2
 * (c) 2007-2008 Steven Levithan <stevenlevithan.com>
 * MIT license
 * Includes enhancements by Scott Trenda <scott.trenda.net> and Kris Kowal <cixar.com/~kris.kowal/>
 *
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.
 */
_class("DateFormat", "", function(){
	// For convenience...
	Date.prototype.format = function(mask, utc){
		return DateFormat.format(this, mask, utc);
	};
	// Some common format strings
	DateFormat.masks = {
		"default"       : "ddd mmm dd yyyy HH:MM:ss",
		"shortDate"     : "m/d/yy",
		"mediumDate"    : "mmm d, yyyy",
		"longDate"      : "mmmm d, yyyy",
		"fullDate"      : "dddd, mmmm d, yyyy",
		"shortTime"     : "h:MM TT",
		"mediumTime"    : "h:MM:ss TT",
		"longTime"      : "h:MM:ss TT Z",
		"isoDate"       : "yyyy-mm-dd",
		"isoTime"       : "HH:MM:ss",
		"isoDateTime"   : "yyyy-mm-dd'T'HH:MM:ss",
		"isoUtcDateTime": "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
	};
	// Internationalization strings
	DateFormat.i18n = {
		dayNames: [
			"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
			"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
		],
		monthNames: [
			"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
			"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
		]
	};
	var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|\"[^\"]*\"|\'[^\']*\'/g;
	var timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g;
	var timezoneClip = /[^-+\dA-Z]/g;
	function pad(val, len){
		val = String(val);
		len = len || 2;
		while(val.length < len) val = "0" + val;
		return val;
	}
	// Regexes and supporting functions are cached through closure
	DateFormat.format = function(date, mask, utc){
		// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
		if(arguments.length == 1 && (typeof date == "string" || date instanceof String) && !/\d/.test(date)){
			mask = date;
			date = undefined;
		}
		// Passing date through Date applies Date.parse, if necessary
		date = date ? new Date(date) : new Date();
		if(isNaN(date)) throw new SyntaxError("invalid date");
		mask = String(DateFormat.masks[mask] || mask || DateFormat.masks["default"]);
		// Allow setting the utc argument via the mask
		if(mask.slice(0, 4) == "UTC:"){
			mask = mask.slice(4);
			utc = true;
		}
		var _ = utc ? "getUTC" : "get",
			d = date[_ + "Date"](),
			D = date[_ + "Day"](),
			m = date[_ + "Month"](),
			y = date[_ + "FullYear"](),
			H = date[_ + "Hours"](),
			M = date[_ + "Minutes"](),
			s = date[_ + "Seconds"](),
			L = date[_ + "Milliseconds"](),
			o = utc ? 0 : date.getTimezoneOffset(),
			flags = {
				"d"   : d,
				"dd"  : pad(d),
				"ddd" : DateFormat.i18n.dayNames[D],
				"dddd": DateFormat.i18n.dayNames[D + 7],
				"m"   : m + 1,
				"mm"  : pad(m + 1),
				"mmm" : DateFormat.i18n.monthNames[m],
				"mmmm": DateFormat.i18n.monthNames[m + 12],
				"yy"  : String(y).slice(2),
				"yyyy": y,
				"h"   : H % 12 || 12,
				"hh"  : pad(H % 12 || 12),
				"H"   : H,
				"HH"  : pad(H),
				"M"   : M,
				"MM"  : pad(M),
				"s"   : s,
				"ss"  : pad(s),
				"l"   : pad(L, 3),
				"L"   : pad(L > 99 ? Math.round(L / 10) : L),
				"t"   : H < 12 ? "a"  : "p",
				"tt"  : H < 12 ? "am" : "pm",
				"T"   : H < 12 ? "A"  : "P",
				"TT"  : H < 12 ? "AM" : "PM",
				"Z"   : utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
				"o"   : (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				"S"   : ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
			};
		return mask.replace(token, function(_0){
			return _0 in flags ? flags[_0] : _0.slice(1, _0.length - 1);
		});
	};
});